public string tooltip_text { get; set; }

Sets the text of tooltip to be the given string.

Also see [method@Gtk.Tooltip.set_text].

This is a convenience property which will take care of getting the tooltip shown if the given string is not null : [property@Gtk.Widget:has-tooltip] will automatically be set to true and there will be taken care of [ signal@Gtk.Widget:GtkWidget:query-tooltip] in the default signal handler.

Note that if both [property@Gtk.Widget:tooltip-text] and [property@Gtk.Widget:tooltip-markup] are set, the last one wins.